Mosara Thiirn, a female Human technician who defected from the Rebel Alliance, later found employment as a field engineer for the Hydrospeare Corporation. Initially, she was a Rebel SpecForce technician, serving on a technical frigate.
Thiirn participated in the Battle of Archais, where the forces of the Rebel Alliance SpecForces (including Shroud Team, Midnight, and Storm Squadrons belonging to Eclipse Team) engaged with Imperial forces in the seas surrounding the planet of Archais.
During this battle, with the Rebel forces facing a dire situation, she made the decision to abandon her post, surrendering both herself and her ship to the Imperial commander, Lieutenant Colonel Freja Covell. This act resulted in significant animosity towards her from the surviving Rebels of the battle, who held her accountable for the deaths of many of their comrades.
However, Covell quickly realized that Thiirn's defection provided little strategic advantage to the Empire. As she was stationed on a mobile base, Thiirn possessed no knowledge of the locations of any Rebel bases, and all of the Rebel officers she knew were already highly prioritized on Imperial Intelligence's wanted lists. While her defection offered some immediate tactical benefits during the battle, it proved useless in causing further harm to the Alliance, regardless of her intentions.
Thiirn transitioned into a role as a field technician for Hydrospeare Corporation, an organization aligned with the Empire, and eventually became a field engineer for the prestigious Design Team Beta. She labored under the delusion that her work was essential to the team. A slender woman with fair skin, Thiirn styled her dark hair into braids, adhering to the Imperial military regulations for female officers on fleet vessels, despite not being an Imperial officer herself.
Akul Witig, a Rebel veteran who fought at Archais, authored a report concerning Thiirn, stipulating that Eclipse Team was authorized to execute Thiirn if she were to be found. General Airen Cracken preferred to capture her alive, but understood that such an outcome would be impossible if Witig or P. Essex Yerac located her first.